Fuel poverty campaigners have written to Prime Minister David Cameron demanding that party leaders act on the "national crisis" of cold homes.
The UK is second only to Estonia among European nations for the number of people who are struggling to pay their energy bills, according to research by the fuel poverty alliance Energy Bill Revolution.
It came as the Government urged people to use their heating this winter as part of a plan to prevent some of the thousands of avoidable deaths that occur each year.
Public Health England (PHE) says people should keep their homes warm, with living room temperatures of 21C (70F) and bedrooms and the rest of the house heated to 18C (65F).
It says temperatures above this "may waste money" but below this "may risk your health".
If people are unable to afford to heat all their rooms, they are advised to heat their living room during the day and bedrooms just before going to bed.
Energy Bill Revolution, which includes Age UK, Barnardo's, Consumer Futures and National Energy Action, has told political leaders that investment in "super insulation" for the nation's homes is the only way to end the "scourge" of fuel poverty and the best way to bring down energy bills.
It said "woeful" levels of insulation have led to Britain's homes falling "way behind" those of comparable European countries such as Sweden, Germany and the Netherlands.
The alliance said the wholesale cost of gas in the UK was much lower than in most European countries but households paid much higher bills due to the amount of heat lost from homes.
There are more than five million UK households living in fuel poverty, defined as spending more than 10% of their income on energy.
The Energy Bill Revolution warned party leaders that by focusing on "short-term solutions" to the energy bill crisis, such as price caps, windfall taxes and cutting green subsidies, they were "ignoring the only way to truly solve the energy bill crisis".
Energy Bill Revolution campaign director Ed Matthew said: "Our political leaders are falling over themselves to come up with headline-grabbing ways to cut energy bills yet they fall woefully short of a true solution to the energy bill crisis.
"By far the biggest opportunity to cut energy bills is to fully insulate the UK's leaky homes. No other investment can do so much for so many. If the Government is serious about solving this crisis they must make insulating homes the UK's number one infrastructure priority."
The PHE recommendation to keep homes warm was included in its Cold Weather Plan for England published in collaboration with the Department of Health, NHS England and the Local Government Association (LGA).
It said there are "too many avoidable deaths each winter", with just over 24,000 annually in England and Wales.
The "causes are complex, interlinked with fuel poverty, poor housing and health inequalities, as well as circulating infectious diseases, particularly flu and norovirus, and the extent of snow and ice," it added.
As part of its advice to the public, the report says people who are eligible for their flu jab should get one, homes should be heated and measures taken to reduce heat waste, such as fitting draught-proofing to seal any gaps around windows and doors.
It also mentions loft insulation, keeping curtains closed to keep in heat and making sure radiators are not obstructed by furniture or curtains.
Furthermore, people should look after themselves with plenty of hot food and drinks, five portions of fruit and veg a day, and wearing layers.
Dr Paul Cosford, director for health protection and medical director at PHE, said: "In colder weather, keeping yourself warm is essential to staying healthy, especially for the very young, older people or those with a chronic condition such as heart disease and asthma.
"There are a range of health problems associated with cold housing and winter weather, but in particular, a cold indoor or outdoor environment can make heart and respiratory problems worse, and can be fatal.
"This is why the Cold Weather Plan sets out a series of actions that health and social care organisations, voluntary groups, and individuals can take and plan for cold temperatures to help reduce cold-related illnesses and deaths."